One- and two-magnon Raman scattering from the quasi-two-dimensional Ising antiferromagnet Rb2CoF4

Abstract

The antiferromagnet Rb2CoF4 is a good example of a two-dimensional Ising model system. One- and two-magnon Raman scattering in Rb2CoF4 is presented with particular emphasis on the temperature dependence of the AFMR. The position of the two-magnon peak cannot be explained by the S=1/2 model. A more realistic model for the magnon-magnon interaction in cobaltous compounds is obtained by diagonalising the single-ion Hamiltonian of Co2+, yielding a two-magnon frequency in fair agreement with the experimentally observed value.